Forgive my ignorance, but I know nothing about lens design, 6 elements, 8 elements, plasmats, hazmats, and so on. My question is whether there is any sharpness difference between the Rodenstock Sironar-S vs. the "N." I am responsible for doing some super-high-resolution copywork of large illustrations (the glass on my old Caltar 300mm is beat to hell, but it's the right focal length). My shooting distance is about 7-10 feet (which I don't think moves it into the macro range). The client's goal is making huge Lightjet enlargements of the resulting 8x10 sheets scanned to digital.
I know the "S" has a larger image circle, but I don't need a lot of movement. The "N" would thus be a logical choice if the two series are equally sharp (there are two 300mm "Ns" -- I think -- on Ebay right now, although because the language in the two ads is almost identical despite sellers on different continents I'm suspicious of both, and one doesn't say "N"). But while searching the archives to see if this has been addressed, I saw Chris Jordan's post saying that he had found the answer to his sharpness quest in the Apo "S" series, so maybe there is a difference? And what about the "APO" designation? Are all Rodenstock Sironars going to be APO, or are there older "S" and "N" models that aren't? Should I care? (The illustrations to be copied are in color fwiw.)
For this current job, at least, "sharpness" is my biggest priority -- not weight, or filter size, or maximum aperture, or even cost (I'm not paying, just doing, and can sell the lens after the job is done if I don't think I'll use it again.) Any lens gurus able to comment?